"It's an inquisition. It's not a trial," Mohammed said in broken English, his voice rising, "After torturing they transfer us to inquisition-land in Guantanamo."

The former No. 3 al-Qaida leader explained he believes only in religious "Sharia" law and railed against US President George W. Bush for waging a "crusade war". The judge, wearing a crewcut and black robes, warned Mohammed that he faces execution if convicted of organizing the attacks on America. But Mohammed said he welcomes the death penalty.

"Yes, this is what I wish, to be a martyr for a long time," Mohammed declared. "I will, God willing, have this, by you."

Mohammed said he would represent himself at his war crimes trial and two other detainees quickly followed suit: Binalshibh and Waleed bin Attash, who allegedly selected and trained some of the hijackers.

"It hardly comes as any surprise that after holding individuals in solitary confinement for five years and subjecting them to torture, these detainees would reject the legal system and offers to represent them," said Anthony D. Romero, executive director of the American Civil Liberties Union in New York.

The Bush administration has acknowledged that Mohammed was subjected to harsh interrogation techniques including waterboarding – a technique that gives the sensation of drowning – in secret CIA custody before he was transferred to Guantanamo in 2006.

In this image reviewed by the US Military, a US trooper exits a tent at Camp Justice, part of the legal complex of the US Military Commissions, at Guantanamo Bay US Naval Base, Cuba, Thursday, June 5, 2008. The accused mastermind of the September 11 attacks and four alleged confederates faced a military judge in their long-awaited first appearance before a war-crimes tribunal. [Agencies]